fairchild



1,632,394- Jlme 1927 w. L. FAIRCHILD APPARATUS FOR PRODUCING PNEUMATIC TUBES Filed Oct. 19, 1925 3 Sheets-Sheet l ,2 20 jLzz 5 26 M M El w HELL- W R@ M a I lN VEN TOR flu ffR A fimrcH/m ATTORNEY June 14,1927.

w. FAIRCHILD APPARATUS FOR PRODUCING PNEUMATIC TUBES Filed Oct. 19, 1925 3 Sheets-Sheet INVENTOR MATE! L/ /ACH/LD ATTORNEY J1me 1927' w. L. FAIRCHILD APPARATUS FOR PRODUCING PNEUMATIC TUBES 1925 3 Sheets-Sheet Filed Oct INVENTOR ML 75/? L fZ/xcmm ALITORNEY Ito Patented June 14, 1927.

UNITED STATES WALTER L. ,FAIRCHILD, OF NEW YORK. N. Y,

APPARATUS FOR IRODUCING PNEUMATIC TUBES.

Application filed October 19, 1925.

This invention relates to a new and improved apparatus for producing hollow articles out of raw rubber compound. more particularly to new and improved apparatus or vuicanizing tubes formed of raw rubber compound to produce pneumatic tubes and the like.

One of the objects of the invention is to provide an apparatus for producing seanr less pneumatic tubes from spliced tubes formed of raw rubber compound. wherein all the material composing the tube is thoroughly and uniformly vulcanized.

Another object of the invention is to provide new and improved apparatus of the. above character. which may be operated more expeditiously than has been possible to operate inner tube vuleanizing apparatus as hitherto constructed.

A further object of the invention is to provide inner tube vulcanizing apparatus wherein individually heated molds are employed, into which the tubes are positioned before vulcanization and wherein an inert gas, such for instance as carbon dioxide, is maintained under pressure and predetermined temperature within the tube during the vulcanizing operation.

Other objects and aims of the invention,

. more or less specific than those referred to above. will be in part obvious and in part pointed out in the course of the following description of the elements, combinations, arrangements of parts and applications of principles. con tituting the invention: and the scope of protection contemplated will be indicated in the appended claims.

in iii accompanying drawings wherein I have illustrated a preferred form of embod ment of my improved apparatus Figure 1 is-a view in side elevation. partly in section of a portion of my im 'n'oved apparatus.

Figure 2 is a view showing a portion of the mold in vertical section and other portions of the apparatus more or less diagrammatically.

Figure 3 is a view of a portion of the apparatus, showing the unvulcanized tube resting in the mold after having had one of the operations of the machine performed thereon.

Figure 4 is a view of a portion of the apparatus. showing the tube resting in the mold after having been subjected to another or further operation of the machine.

Serial No. 63,368.

Figure 5 is a vertical sectional view of the mold, showing the tube enclosed within the sections of the mold ready to be subjected to the vulcanizing operation.

Figure 6 is a view similar to Figure 4, showing the mold in a different position, and

Figure 7 is a similar view, showing the parts in the position they occupy immediately subsequent to vulcanization.

Similar reference characters refer to similar parts throughout the several view of the drawings.

Referring now to the drawings, the reference numeral 1 denotes one section of a circular mold, having an ecliptically formed channel 2. constituting one part of the molding or vulcanizing chamber. The reference numeral 3 illustrates the second section of the mold, which is provided with a comple+ nientary molding or vulcanizing recess 4, said mold sections being hingedly connected at 5. so that when the section 3 overlies the section 1 as indicated in Figure 6 of the drawings, a closed chamber ecliptically formed in cross section will be provided between the mold sections, adapted to receive a tube of raw rubber compound, indicated at 6, upon which the vulcanizine: operation is to be performed.

T his tube, which as above stated, is composed of raw rubber compound, has been previously produced. as bv means of a tubing machine, has had its ends brought together in overlapping or abutting relation. and has had a valve stem 7 inserted therein. The tube thus formed is inserted in the channel 2 of the lower mold section 1, which has been previously disposed in a horizontal position, the position of the tube within said mold section being illustrated in Figure 1.

The lower mold section 1, which supports the upper mold section, is mounted upon an arm or support 8. said support being in turn journaled at 9 to an upright standard 10, the construction being such that the mold as'a unit may be swung from its normal horizontal position shown in Figure 1, to the tilted position shown in Figure 6.

The mold sections 1 and 3 are each steamjacketed. the steam chambers of the mold of said sections being respectively indicated at 11 and 12. \Vhile in Lhe present instance the means for supplying the heating medium to the mold sections are not shown, it will be understood that both of said sections are intended to be always maintained at the vu1- canizing temperature required for the particular compound of raw rubber being subjected to the vuleanizing operation.

It will be further understood, of course. that the edges of the mold sections are very nicely machined. so that their meeting edges fit closely together, means being provided to lock the mold sections in th ir clired position against the gaseous pressure ontined in the tube within the mold being subjected to the "ulcaniziug operation.

Referring now to the apparatus employed for inserting and withdrawing the gases utilized within the tube prior and subsequent to the carrying; out of thc Villt'fltlillll ap paratus, the reference numeral 13 indicates a tank adapted to contain under pressure the fluid vulcanizing Illttllllll'l to be employed within the tube. 'hile various inert gases may be emplo ed in this operation. I prefer to employ carbon dioxide gas. which I have found to be an excellent vulcaniaing medium. The supply of gas to the tankil l may be re plenished as required from a high pressure tank 14 through the conduit 15. which may. if desired, be provided with an autonuitieallv operating control valve shown diagrammatb cally at 16. Leading from the tank l3 is a conduit 17, and leading from the conduit 17 are the branches 18 and ill. the former leading to the casing 20 of a two-way valve 21. The casing 20 of the valve 21 is connected with the valve stem 7 of the tube to be vulcanized, as by means of a flexible tube 22.

Leading, from the valve casing 20 is a conduit 2? which connects with a valvecasing 24 of a two-way valve 25. the branch conduit 19 of the conduit 17 being also connected to said valve casing 94. which branch conduit 19 is preferably provided with a pressure reducine; valve 26. Leading from the valve casing 21. is a conduit 37. the other end of which leads into the vacuum tank 28. The reference numeral )9 denotes a vacuum tanl; from which lead a conduit fl which is connected with a valve casing: 3, and leadin}; from the valve casing I ll is a conduit 32 which connects with the casing 23. The valve conduit 3] is provided with a valve 33, operated by means of :1V handle 34. which handle is normally urged into en gageuient with a stop 3.1 by means of the re tractilc spring 3b. the valve II being normally held therebv in a closei'l position. as clearly indicated in the drawings.

Leading from th vacuum tank '2 is a conduit 37 which is connected with the pump 39 driven by mean of a motor fil and leadin; from th pump 29 to the ta k 19, is a conduit 40. The valve member 2i is provided with a ub lantially L-shaped pa sagi way 41. said valve member being adapted to be ro at d to such position that conimuni cation will be established between the branch conduit 18 and the flexible tube 22. or between the latter and the conduit 23. or to he moved into such position as will shut 0E all intereomn'iunication between 1d conduits.

The valve member 2.3 provided with an i -Sll2l] P l pas ageway 12. said valve member being adapted to be rotated to such positions as will ertal'ilisli comluunication be tween he conduits 23 and 2?. or the conduit 23 and betw en branch conduit 19. or it may be rotated to a neutral position whereby communication between all of said conduits may be shut. oil. The platform or support 8 provided with a. link 43 which is con nected to the end or the arm 4-4 extending from the valve 2i. so that" when the mold is swung upon its pivotal axis to the position indicated in Figure (3. said valve member 21 will be rotated so that communication will be shut ott' between the condu t 2-? and the flexible tube and communication established between the branch conduit 18 and the flexible tube 22 for a purpose which will be hereinafter described,

Referring now to Figure 2 of the drawings. I have provided means whereby. if desired. the carbon dioxide gas may be dis-- charged into the tube to be vuicanized at any desired temperature and pressure. This means coneists of a steam coil t5 located in the tank 13 which may receive its supply of steam from any desired source.

l have found that in some, in tan desi'ri'ible to discharge the vulcair .agr gas into the tube to be vulcanized in a relatively cool condition. so as to slightly retard the heating; of the unvulcanized rubber eo1npound due to its contact with a heated eurface of the lower section of the mold. thereby to prevent such softrning ot' the rubber compound as might permit the tube to l p or fall over the edge of the mold. whereby when the upper section i: positioned thereon the tube might be pinched bctw: en the meeting edges ot the mold sections. lt is f course. desirable that the vuh'an aiug gin be tliicharged into the tube to rc vulcanized at a temperature as clo e to the vuleanizing: teriperature of the mold as it is po sible to do without soft ning the raw rrblier compound before the mold sections are clo ed about the tube and the latter expan'led within the mold immediately prior to the starting: of the volcanization operation. The reason for this is that it is desirable to bring the temperature within the tube to the temperature exteriorly thereof as quickly as possible so that a uniform vulcanization ot' the tube wall may he accmnplished. and it is al o desirable in order that time be not consumed in heating th gas within the tube by the application of the exterior h at of the mold.v y the provision. thereforei of means whereby the temperature f the vulrainiziug gas may lit".

lit 0 be regulated to a nicety, I obtain the aforementioned desideratum and am able to heat the carbon dioxide to the safety limit, which limit of c urse depends upon the size of the tube and t e composition being treated.

aving thus described the construction of ,this embodiment of my invention, the operation thereof may now be understood.

Assuming the parts to be in the positions shown in Figure 1, with the tube 6 partly collapsed and inserted in the lower section of the mold in the position shown in said tigure and assuming a vacuum to have been established in the tank 29, the tank 13 to contain carbon dioxide gas under suitable pressure and temperature. a vacuum to have been established in the tank 28, and the valve stem 7 connected with the flexible tube 22: in the first operation, the operator swings the valve lever 34 to open for an instant the valve 33, whereby any air present in the partially collapsed tube will be sucked therefrom through the conduit 30 by the vacuum tank 29, so that the tube will take on the appearance of Figure 3, that is to say, the tube will be entirely collapf-ed within the mold section 1. volved to establish communication between the conduit 23 and the branch conduit 19, whereupon the carbon dioxide gas will flow from the tank 13 through the conduit 17, the branch conduit 19, the reducing valve 26, the passageway 42 of the valve 25, the conduit 23, throu h the passageway 41 of the valve 21, the fl zxible tube 22, through the valve stem 7 to the collap d tube about to be vulcanized.

It is intended in this operation to project just a suflicient amount of carbon dioxide gas into the tube to expand it, so that it will take on the form substantially shown in Figure 4 of the drawing, thatis to say, the tube will be caused to engage with the wall of the val canizing channel of the lower section I of the mold, the upper end of the tube projecting slightly above the edges of the channel 2 of said lower section. The reducing valve 26 intended t so cut down the pressure of gas that there will be little danger of bursting or injuring the tube through this operation.

\Vhen this operation has been accomplished. the valve 25 is closed. The upper section 3 of the mold is then swung downwardly upon the lower section. and the sections tightly locked together. tl ig. 5) whcrc by the partly cxpanijlcd tube lies within the circular vulcanizing: channel of the mold. ready for the vulcanizing operation. It will be understood that allot these operations are performed very expeditiously. because of the fact that,- the mold sections i and 3 have been previously heated to the vulcanizing' temperature, and are at all times maintained at such temperature, it being ntial to keep the unvulcanized rubber time iron wilting Thevalve 25 is then rewithin the mold due to its contact with the heated section 1. The projection of the cold carbon dioxide or like gas into the tube also assists in maintaining the, tube from injury until the upper section has been closed down upon the lower section to enclose the tube prior to the vulcanizing operation, which is now ready to be carried on.

When the upper section has been closed down upon the lower section, as above described, the operator then quickly tilts the mold as a unit to the position shown in Figure 6 whereby the valve 21 will be moved to establish communication between the interior of the tube to be vulcanized and the source of carbon dioxide supply in the tank 13, through the valve stem 7, the flexible tube 22, the valve passageway 41. branch conduit to. anrl the conduit 17. The inner tube 6 will thereupon be further expanded by the heated carbon dioxide gas, so that it; will lie in close contact with the wall of the vulcanizing chamber, such pressure being held within the inner tube as will maintain its close engagement with the wall of said vulcanizing chamber during the vulcanizing operation.

The mold is permitted to remain in the position shown in Figure 6 of the drawing durin, the entire vulcanization operation, the time of which will, of course, be determined by the relative heat of the mold, and the particular compound of which the tube is composed. The holding of the mold in the inclined position during the vulcanizing operation. l regard as most important, because when the mold is in that, position it is pos: sible to drain the upper section thereof of its comlensation, which draining is easily accomplished with the lower section whatever its position. I am thereby able to main tain both sections of the mold in an equally heated condition during the vulcanization.

llhen the vulcanizing operation has been completed, the mold will be swung to its horizontal position, whereby communication will again be established between the mterior of the vulcanized tube through the valve stem 7, flexible tube 22, valve passageway it, and the conduit 23. The valve 25 then is swung to the position shown in Figure 7, thereby connecting the conduit 23 through said valve passageway 42 and conduit 27 with the vacuum tank 28. whereby the source of suction will quickly remove all of the carbon dioxide gas in the vulcanized tube, causing it to collapse, within the mold. thereby disengaging itself from the wall of the vnlcanizing chamber. The mold is then opened. and the vul anizedtube removed, whereupon the apparatus is in position to perform another vulcanixing operation similar to that just described.

The pump 39 serves to maintain a vacuum within the tank 28, pumping the carbon ill) dioxide gas back into the supply tank 13, it being, understood that. in practice, automaticaily operating derices will be employed to start and stop the pump 38, the reducing valve 15 operating automatically to maintain a constant predetermined pressure with in the tank 13. when the supply of carbon dioxide gas in the tank if) is required to be replenished from the main carbon dioxide supply tank H.

it will accordingly b een that I have pr vided apparatus well adapted. among others. to attain all the ends and objects ahore pointed out. in a very simple manner. By means of my imprmcd apparatus. seamles inner tubes may be pwalnce-l in such a way that there is no unequal stretching of the unvul anizcd rubber trom which the \ulcaniawl tube is formed. the wall of the tube thus formed being of uniform thickness and evenly vulcanized throughout. M reover. the presence f the car on dio'x'idc gas in the tube prior to the starting of the rulcanizing: operation insures against injury of the tube while the latter is being: enclosed ithin the sections of the mold. inasmuch as carbon dioxide or like uncoinlcnsihle gas within the safe temperature which may he used in rubber \ulcanization i empioycd within the inne" tube durin; the rutcanizing operation. the inner wall of the tubiis in a dry condition during and after vulanization.

The initial sucking out of the air in the unrulcanized tube before carbon dioxide "as is projected therein insures against mixing air with the carbon dioxide gas. whereby the latter will not be diluted. so that it may be used repeatedly in carrying out the afore mentioned operation.

It. will be. understood that various changes may he resorted to in the form. construction and a angrement of the several parts without diparting from the spirit. and scope of my invention: and hence. I do not intend to be limited to the details herein shown and described except as they ma he included in the claims.

llaving thus described my invention, what, i claim as new'and desire to secure by Letters Patent, is

1. In an apparatus of the class described, in combination, a mold comprising a pair of uniting sections having complementary vulcanizing channels, said mold sections when positioned in mating relation forming a continuous circular ulcaniZing chamber adapted to receive, a tube to be vulcanized, means for withdrawing air from said tube. means for introducing an inert gas into said tnlic partially to expand it within the lower sect'ion of the mold, said upper section being adapted to be closed u .on said lower section to enclose said partially expanded tube, automatically controlled means for thereafter introducing a further quantity of said inert vulcanizing; gas into Said tube for expanding it within said mold. and means for withdrawing said vulcaniying gas from said tube when the vulcanizing operation there,- on has been completed.

2. In an apparatus of the class described, in combination. a mold comprising a pair of mating sections having complementary vulcanizingr channels. said mold sections when positioned in mating relation forming 9. contiuu us cir ular vulcanizing chamber adapted to receive a tube to be vulcanized, means For withdrawing air from said tube. means for introducing an inertgas into said tube partially to expand it within the lower section of the mold. said upper section being adapted to he closed upon said lower section teenclo e aid partiall v expanded tube, uutomaticullv controlled means for therea tier introducing a further quantity of said insert vul anizing eras into aid tube for expalulingf it within said mold. means for preh ating FHii'l inert rulcanizing' gas and means for withdrawing said vulcanizing gas from said tube when the vulcanizing operation thereon has been completed.

3. in an apparatus of the class described, in combination, a mold comprising a pair of mating sections having complementary vulcanifm; channeis, said mold sections when ositioned in mating relation forming a continuous circular vulcanizing chamber adapt;- ed to receive a tube to be vulcanized, means for withdrawinir air from said tube. means for introducing an inert gas into said tube partially to expand it within the lower section of the mold. said upper section being adapted to be closed upon said lower section to enclose said pa rtially expanded tube, automatically controlled means for thereafter introduciug a. further quantity of said inert vulcurving: gas into said tube for expanding it within said mold. means for controlling the temperature of said inert vulcanizing gas prior to its introduction to said tube and means for withdrawing said vulcanizing gas from said tube. when the \ulcanizing open ution thereon has been completed.

4. Tu an apparatus of the class described, in combination, a movable mold comprising a pair of mating sections having complemcutary vulcanizing channels. said mold sections when positioned in mating: relation forming a continuous circular vnlcanizing chamber adapted to receive a tube to be 7111- canized, suction means, means for supplyin a gas. a valve, means for connecting said valve with a tube within the mold, and mechanism connecting the mold with the valve whereby movement of the mold to one position will open communication between the tube in the mold and the suction means and movement; of the mold to anothonposition will shut otf communication between the tube and the suction means 1nd open (30mmnnication between thv tube and the means for supp )ing a gas.

5. 111 m1 ag qmrutw ui' H11. (hi sio-whvihed 3n combination. :1 yiwmlh' nmumled meld comprisinga 1mm mi muting awlium having vhnmmis,

L ply mg a gas.

a valve, means fur mlmurlixng Bald Valve with :1 tube wu'hzu the muhi and 5mm! in maiim: TU".

mmimniqn mum-wring the mnld with flu :zfh: n'hvz'ui 1w whims! 01' the mold about its pivot in om flil'uciiun WEN open 0mm munimnimi iu-iwch 11 i' \ubu in mu! H10 sm-iiml 111mm um] nam'onwm 0f Hm mull! uimut 5 pin! in 2,112 uppoaitu dil'lgw \Em: ME? dud mi mmumnimtion Lmwwn 23w :w-iim: Imam and 0 n v V mum s1 (he tum: and 1e in M-Unmay xvi 

